There are merchandise checkout systems that use visual recognition or verification at a point of sale (POS) to prevent UPC fraud. These systems generally employ a database of images or other visual information representing merchandise that is then compared with images acquired during the checkout process. This database of visual information must be built and regularly updated to account for new merchandise and for changes in packaging of merchandise. For a checkout system that does automatic ring up, the database for visual recognition in a modern grocery store would require tens of thousands of items. Presently, a database of visual images for either system would be created and updated manually, which can be impractical because of the amount of time and effort involved. There is therefore a need for a system that can automatically create and update a visual database based on information acquired during the checkout process.